I use it every three or four years I reckon and it always works. Didn't realise how old it was until a couple of years back when a mate found it and came running in from the bathroom with it (the nosy twat).

Used half the tin & put the rest in a small tupperware box. This would be about a year ago. They're still in the fridge and neither I nor Mrs TD dare open the box for fear of unleashing a fishy apocalypse

part of a pack from when I was about 7 and got worms. I have been paranoid ever since so always had an emergency one in my medicine cabinet, from leaving home for uni and beyond. Part of the original pack. I doubt it works but I am not having a nice of crawing at my arse again.